I can't seem to replicate, but I'm using 10.13.4. Have you tried updating? Also, did you check in System Preferences >> Keyboard >> Shortcuts to see if they were overridden somehow?
– AllanMay 22 '18 at 7:25

1

@Allan No I did not update. No shortcut overridden. everything is on default
– LearnerMay 22 '18 at 7:28

2

Try in Safe Mode (hold Shift while booting) to see if there's a conflict with something that get's loaded. Also, try creating another user account to see if the problem persists there.
– AllanMay 22 '18 at 7:33

1

To switch tabs in Chrome (and almost any application that supports tabs in a single window), try the shortcut Command + { and Command + }.
– Nimesh NeemaMay 22 '18 at 9:00